Abstract:
Photon up-conversion in tellurite glass exhibits a strong NIR emission and has achieved significant success in the field of photonics. Herein, the review offers an overview of quantitative and qualitative studies on the up-conversion phenomenon in tellurite-based glasses. Rare-earth ion doped tellurite glasses have emerged as one of the most versatile glassy platforms in modern photonics owing to their unique combination of low phonon energy, extended infrared transparency, high refractive index, significant rare-earth ion solubility, and exceptional nonlinear optical response. The review provides a comprehensive overview of the underlying mechanisms governing up-conversion, with emphasis on energy-transfer up-conversion pathways to correlate emission behaviour with host composition. The novelty in this system is its high rare-earth-ion solubility, which enables incorporating multiple rare-earth ions and efficient co-doping strategies to tailor up-conversion properties. Here we have identified three key factors governing photon up-conversion in Er sup(3+0, Ho sup(3+), Tm sup(3+), Dy sup(3+) and Sm sup(3+) ions doped/co-doped tellurite glass systems: hydroxyl group-induced concentration quenching, excitation wavelength and the up-conversion emission. The up-conversion properties and Judd-Ofelt parameters (omega2, omega4, omega6) were systematically compared for a common host matrix while varying the rare-earth dopant. Moreover, the review also highlights the current state-of-the-art application and the roadmap for optimizing rare-earth ions doped tellurite glasses towards next generation photonic applications and quantum technologies.
